The Light Emitting Diode (LED) has increasingly been the most powerful competitor among solid state lighting and liquid crystal display backlight sources due to its prominent features of the lifetime of use, the high lumen efficiency, a low drive voltage, etc.
A leaded package adopted for an early light emitting diode has gradually been replaced with a surface mount package along with the advancement in the art of packages. The surface mount package is generally divided into two types, one of which is a Plastic Leaded Chip Carrier (PLCC) where the square-shaped 32-pin package is provided with leads extracting in a T-shaped way from four sides of the package and has a figure dimensioned much smaller than that of a DIP package, and the other of which is a Ceramic Leaded Chip Carrier (CLCC) with leads extracting in a T-shaped way from four sides of the package. This package technique is typically applied as a package of an ultraviolet erasable EPROM with a window, a microcomputer circuit with an EPROM, etc., and can also be referred to as QFJ or QFJ-G.
There is also disclosed in the prior art another package technique of a light emitting diode, and with particular reference to FIG. 1, the package structure of a light emitting diode includes an LED bare chip and a silicon substrate 2, the LED bare chip includes a substrate 10, an N-type epitaxial layer 11 and a P-type epitaxial layer 12, the silicon substrate 2 is provided with two separate deposited metal layers 32 and 33, the P-type epitaxial layer 12 and the N-type epitaxial layer 11 are flip-bonded over the metal layers 32 and 33 respectively through solder balls 40 and 41, the doped first isolation layers 22 and 23 are further arranged respectively in areas where the metal layers 32 and 33 are bonded with the silicon substrate 2, a U-shaped notch is arranged over the upper surface of the silicon substrate 2, the LED bare chip is located inside the U-shaped notch, the U-shaped notch is filled with transparent and insulating resin 7 and has the bottom and sides thereof covered with the metal layers 32 and 33, the outer surfaces of the metal layers 32 and 33 are light reflecting surfaces, and the second isolation layers 51 and 53 are arranged respectively between the metal layers 32 and 33 and the silicon substrate 2. The LED package structure further includes a protection layer 6 with which the outer surfaces of the metal layers 32 and 33 are covered to prevent a short circuit therebetween.
More information on the above technical solution can further be found in Chinese Patent No. 200620058968.
However in the above technique, electrodes of the LED extracts through the metal layers 32 and 33 formed on the same side of the silicon substrate, and this may result in a relatively large volume of the package; and extraction of the electrodes has to be achieved through gold wiring in the subsequent structure of the package, and also the gold wires have to be protected through resin sealing thereof to seal them in plastic, and then the electrodes are extracted, which may result in a further increased volume of the package.
Moreover in the above technique, the use of resin sealing in plastic may make the light emitting diode sealed completely, so that it may be difficult to dissipate the generated heat.
Therefore, a new LED package is desired.